You guessed at it, it's now been more or less confirmed. Blizzard leaked a little spoiler that after the airship battle you would face the Lich King's most fearsome champion.

Well it looks like if you're horde, that champion is Bolvar, and if you're alliance that champion is Saurfang Jr. The only question is, do we redeem these heroes and thus redeem ourselves in the eyes of the opposite faction (Note Saurfang saying they needed to save Bolvar so that the alliance will like the horde again) or will we just up and kill them and yet again get into a petty argument about who killed whose champion when they were already lost to the Lich King. My bets are on the latter.